1. Field of the Invention
The present invention is generally related to a tilt switch and, more specifically, to a switch which utilizes a moving member to bridge two conductors and provide an electrical connection therebetween under one tilting condition and to separate the conductors and deprive electrical communication between the two conductors under an alternative tilting condition.
2. Description of the Prior Art
Many different kinds of tilt switches are known to those skilled in the art. Perhaps the most well known is the mercury switch which finds world, wide use in thermostats. The well known mercury switch and other alternative tilt switches respond to changes in their attitude relative to a horizontal plane by making or breaking electrical contact between preselected conductive devices.
U.S. Pat. No. 4,686,335, which issued to Grant on Aug. 11, 1987, discloses a shock sensor switch which is sensitive to vibration. It has a pair of spaced apart parallel contacts that are housed in a switch body and a movably supported mass inside a chamber in that body. The mass is supported by conductive members in the form of a pair of bars which are secured in the mass and located between the two contacts with the center of gravity of the mass being spaced from the points of contact between the contacts and the bars so that bars are urged against the contact by a lever action as a result of the gravitational force acting on the mass.
U.S. Pat. No. 4,467,154, which issued to Hill on Aug. 21, 1984, describes a gravity switch. A molded cup-shaped dielectric member and a cup-shaped conductor member are pressed together to comprise an integral dimensionally stable sealed enclosure for a contact member which is moveable axially therein for selectively making or breaking an electrical connection between the cup-shaped conductor member and a second conductor extending axially through and sealed within the base of the cupshaped dielectric member. The enclosure has an interior cylindrical surface of optimum diameter for the axially moveable contact member which comprises a metallic ball that is also of optimum diameter for any given size switch.
U.S. Pat. No. 4,618,746, which issued to Schwob et al on Oct. 21, 1986, discloses a ball actuated position sensitive switch which operates as a multi-directional switch. It comprises a housing in which at least two electrical contacts are arranged relative to one another, a tilting member that is supported in the housing by means of a tilting part and having a control part extending in the vicinity on one of the electrical contacts. The ball is carried by a surface of the tilting member which is opposite the tilting part and has a profile in the form of a cup.
It is important, in many tilt switch applications, that the switch be sensitive to very small magnitudes of angular change of the switch relative to a reference plane, such as a horizontal plane. For example, in a household thermostat, very small angles of tilt must be responded to by a change in an electrical connection to either make or break a circuit in response to that minor change in angular relationship between the tilt switch and a reference plane.